Areca nut (AN) is an addictive carcinogen used by about 200-600 million people worldwide. Some AN components are shown to induce apoptosis; however, we previously demonstrated that AN extract (ANE) and the 30-100kDa fraction of ANE (ANE 30-100K) induced autophagy-like responses, such as swollen cell morphology, empty cytoplasm, acidic vesicles, ...

To evaluate the anti-apoptotic effects of Joongpoongtang 05 (JP05), a mixture of plant extracts, on a Neuro-2a (N2a) cell model of oxygen and glucose deprivation (OGD)/reperfusion (OGDR), a neuroblastoma cell injury model was induced by OGDR. This model allowed us to investigate cerebral ischemic changes and the protective effects of ...

As iron ions may participate in the pathogenesis of cancer and viral infections, the aim of this study was to monitor their influence on proliferation, E6 and E7 oncogene expression and reactive oxygen species (ROS) production in two human papilloma virus (HPV) positive cervical carcinoma cell lines (HeLa and SiHa) ...

In a previous study, we demonstrated that the anticancer synthetic retinoid N-(4-hydroxyphenyl)retinamide (4HPR) redox cycles at the mitochondrial enzyme dihydroorotate dehydrogenase to trigger anomalous reactive oxygen species (ROS) production and attendant apoptosis in transformed human epithelial cells. Furthermore, we speculated that the hydroxyl functional group of 4HPR was required for ...

Type 2 diabetes is a complex disease that is accompanied by elevated levels of nonesterified fatty acids (NEFAs), which contribute to β-cell dysfunction and β-cell loss, referred to as lipotoxicity. Experimental evidence suggests that oxidative stress is involved in lipotoxicity. In this study, we analyzed the molecular mechanisms of reactive ...

Nutrient stress is generally considered from the standpoint of how cells detect and respond to an insufficient supply of nutrients to meet their bioenergetic needs. However, cells also experience stress as a result of nutrient excess, during which reactive oxygen species (ROS) production exceeds that required for normal physiological responses. ...

Mixotrophy is the occurrence of phagotrophy and phototrophy in the same organism. In ciliates the intracellular phototroph can be unicellular green algae (zoochlorellae), dinoflagellates (zooxanthellae), cryptomonads or sequestered chloroplasts from ingested algae. An intermediate mixotrophic mechanism is that where the phagotroph ingests algal cells, maintains them intact and functional in ...

Detection of reactive oxygen species (ROS) released from live macrophage cells (RAW264.7) without any addition of external redox mediators using constant-height and constant-distance mode scanning electrochemical microscopy (SECM) was presented in this Letter. The successful separation of the ROS profile from the topography of cells in the physiological condition was ...

Hypoxia plays an important role in the development of solid tumors and is associated with their therapeutic resistance. There exist three major forms of hypoxia: acute, chronic, and intermittent hypoxia. Previous studies have shown that cancer cells could behave in the form of adaptation to hypoxia in tumor growth, which ...

Throughout alcoholic fermentation, nitrogen depletion is one of the most important environmental stresses that can negatively affect the yeast metabolic activity and ultimately leads to fermentation arrest. Thus, the identification of the underlying effects and biomarkers of nitrogen limitation is valuable for controlling, and therefore optimizing, alcoholic fermentation. In this ...

Although generation of reactive oxygen species (ROS) by NADPH oxidases (Nox) is thought to be important for signal transduction in nonphagocytic cells, little is known of the role ROS plays in chondrogenesis. We therefore examined the possible contribution of ROS generation to chondrogenesis using both ATDC5 cells and primary chondrocytes ...

The totality of functional cardiomyocytes and an intact cardiac progenitor cell pool are key players in the myocardial cell homeostasis. Perturbation of either one may compromise the structural and functional integrity of the heart and lead to heart failure. Reactive oxygen/nitrogen species (ROS/RNS) are important regulators of cardiomyocyte viability; more ...

The acquired capability of tumor cells to migrate and invade neighboring tissues is associated with high metastatic potential and advanced stage of cancers. Recently, signaling molecules such as reactive oxygen species (ROS) and caveolin-1 (Cav-1) have been implicated in the aggressive behavior of cancer cells. However, the roles of specific ...

Chronically elevated concentrations of non-esterified fatty acids (NEFAs) in type 2 diabetes may be involved in β-cell dysfunction and apoptosis. It has been shown that long-chain saturated NEFAs exhibit a strong cytotoxic effect upon insulin-producing cells, while short-chain as well as unsaturated NEFAs are well tolerated. Moreover, long-chain unsaturated NEFAs ...

Research on cell-penetrating peptides for the intracellular delivery of porphyrin compounds has mainly focused on the use of trans-activator of transcription (TAT)-derived peptides and, to a lesser extent, on proline-rich peptides and phosphorescent metalloporphyrins. In this article, we describe a novel phosphorescent oxygen-sensitive probe for intracellular use which comprises a ...

Lomaantha phragmitis sp. nov. is described and illustrated from a specimen collected on dead culms of Phragmites communis in southern China. The fungus differs from other described Lomaantha species in its conidiophores, conidiogenous cells and conidial appendages. Conidial morphology and presence or absence of percurrent proliferation of conidiogenous cells are ...

Central nervous system dysfunctions are among the most significant effects of exposure to ethanol and the glial cells that play an important role in maintaining neuronal function, are extremely involved with these effects. The actin cytoskeleton plays a crucial role in a wide variety of cellular functions, especially when there ...

Among the aldehydes derived from lipid peroxidation, there have been several reports concerning the toxicity of 4-hydroxy-2-nonenal (4-HNE), whereas little information is available about 4-oxo-2-nonenal (4-ONE). In the present study, we examined the effects of 4-HNE and 4-ONE on the cell viability of primary rat hepatocyte cultures. At concentrations of ...

A method for real-time evaluation of cell viability was developed by using oxygen as an endogenous indicator in scanning electrochemical microscopy to monitor the nanoscale height change of a single cell in a physiological environment with a novel Pt nanodisk electrode and a newly designed step-approaching strategy.

Transplanted cells, especially islet cells, are likely to become apoptotic due to local hypoxia leading to graft dysfunction. Isolated pancreatic islet cells depend on the diffusion of oxygen from the surrounding tissue; therefore, access to sufficient oxygen supply is beneficial, particularly when microcapsules are used for immunoisolation in xenotransplantation. The ...

Kidney medulla cells are exposed to a wide range of changes in the ionic and osmotic composition of their environment as a consequence of the urine concentrating mechanism. During antidiuresis NaCl and urea concentrations increase and an efficient urinary concentrating mechanism is accompanied by medullar hypoxia. Medullar hypotonicity increases reactive ...

Myoglobin, a mobile carrier of oxygen, is without a doubt an important player central to the physiological function of heart and skeletal muscle. Recently, researchers have surmounted technical challenges to measure Mb diffusion in the living cell. Their observations have stimulated a discussion about the relative contribution made by Mb-facilitated ...

Photodynamic therapy (PDT), induced by a photosensitizer (PS) encapsulated in a nanostructure, has emerged as an appropriate treatment to cure a multitude of oncological and non-oncological diseases. Pyropheophorbide-a methyl ester (PPME) is a second-generation PS tested in PDT, and is a potential candidate for future clinical applications. The present study, ...

Cell migration is a hallmark of cancer cell metastasis and is highly correlated with hypoxia in tumors. The Boyden chamber is a porous membrane-based migration platform that has seen a great deal of use for both in vitro migration and invasion assays due to its adaptability to common culture vessels ...

The heterotypic interactions of endothelial cells and mural cells (smooth muscle cells or pericytes) are crucial for assembly, maturation, and subsequent function of blood vessels. Yet, the molecular mechanisms underlying their association have not been fully defined. Our previous in vitro studies indicated that Notch3, which is expressed in mural ...

Light in the visible and near infrared region stimulates various cellular processes, and thus has been used for therapeutic purposes. One of the proposed mechanisms is based on cellular production of reactive oxygen species (ROS) in response to illumination. In the present study, we followed visible light (VL)-induced hydroxyl radicals ...

Emodin (1,3,8-trihydroxy-6-methylanthraquinone), a natural anthraquinone derivative found in several herbal medicines, is highly active in suppressing the proliferation of various tumor cells such as breast, hepatocellular, and lung cancer cells under in vitro conditions. The mechanism of emodin-induced apoptosis in esophagus carcinoma cells, EC-109, is not completely understood. In this ...

Biocompatibility of dentin bonding agents (DBAs) and resin composite is important to preserve the pulp vitality after operative restoration. Bisphenol-glycidyl-methacrylate (BisGMA) is one common monomer adding into DBAs and resin. In this study, we found that exposure of human dental pulp cells to BisGMA (>0.1 mM) led to cytotoxicity, G2/M ...

Quenched-phosphorescence oxygen (O(2)) sensing technique allows non-invasive, real-time monitoring of both intra- and extracellular O(2) concentration in respiring samples. Using this technique we investigated O(2) gradients in populations of neurosecretory PC12 cells cultured in 96-well plates and exposed to graded hypoxia at rest and upon metabolic stimulation. Under high atmospheric ...

Arsenic is a well-established human carcinogen; however molecular mechanisms to arsenic-induced carcinogenesis are complex and elusive. The present study identifies a potential biomarker of arsenic exposure, and redefines arsenic-induced signaling in stimulation of cell proliferation. The effect of arsenic exposure on gene expression was evaluated in PBMC of arsenic-exposed individuals ...

Smoking is associated with an increased risk of oral health and dental problems. The aim of this study is to address the hypothesis that nicotine impairs wound healing by increasing reactive oxygen species and inhibiting cell migration, and antioxidants (AOs) may counteract nicotine effects. Primary human gingival fibroblasts (HGFs) and ...

Large-scale tissue engineering is limited by nutrient perfusion and mass transport limitations, especially oxygen diffusion, which restrict construct development to smaller than clinically relevant dimensions and limit the ability for in vivo integration. The goal of this work was to develop a modular approach to tissue engineering, where scaffold and ...

Severe hypoxia has been demonstrated to induce a replication arrest which is associated with decreased levels of nucleotides. Chk1 is rapidly phosphorylated in response to severe hypoxia and in turn deactivates TLK1 through phosphorylation. Loss of Chk1 has been shown to sensitize cells to hypoxia/reoxygenation. After short (acute) exposure to ...

Hirsutanol A is a novel sesquiterpene compound purified from fungus chondrostereum sp in Sarcophyton tortuosum. Its pharmacologic effect has not been reported yet. This study aimed to investigate cytotoxic effect of Hirsutanol A on hepatocellular carcinoma (HCC) cells and its mechanism. Hep3B cells were treated with different concentrations of Hirsutanol ...

Bcl-2 interacting cell death suppressor (Bis), also known as Bag3, has been implicated in anti-stress and anti-apoptotic pathways. In a previous study, we observed a significant induction of Bis in reactive astrocytes of the rat hippocampus after transient forebrain ischemia. To investigate the significance of this induction in ischemic injury, ...

The oxidative stress responses of single MG63 osteosarcoma cells submitted to a brief mechanical stress have been investigated by amperometry at platinized carbon fiber electrodes for monitoring and characterizing the nature and the amounts of the various reactive oxygen (ROS) and reactive nitrogen species (RNS) released. It was thus shown ...

D-penicillamine is an aminothiol that is cytotoxic to cancer cells and generates dose dependent reactive oxygen species (ROS) via copper catalyzed oxidation. However, the delivery of D-pen to cancer cells remains a challenge due to its high hydrophilicity, highly reactive thiol group and impermeability to the cell membrane. To overcome ...

This study was designed to examine the mutual relationship between 8-isoprostane in exhaled breath condensate (EBC) and superoxide anion generation by bronchoalveolar lavage fluid (BALF) cells in patients with sarcoidosis. About 29 patients with sarcoidosis, 34 healthy never smokers (control group for EBC) and 15 healthy never smokers (control group ...

Vascular endothelial growth factor (VEGF) and reactive oxygen species (ROS) play critical roles in vascular pathophysiology and in hematological malignancies. VEGF is supposed to utilize ROS as messenger intermediates downstream of the VEGF receptor-2. NAD(P)H oxidase (Nox) family is a major source of cellular ROS and is implicated in increased ...

In the absence of in vivo measurements, the oxygen concentration within articular cartilage is calculated from the balance between cellular oxygen consumption and mass transfer. Current estimates of the oxygen tension within articular cartilage are based on oxygen consumption data from full-depth tissue samples. However, superficial and deep cell subpopulations ...

Unlike normal cells, tumor cells survive in a specific redox environment where the elevated reactive oxygen species contribute to enhance cell proliferation and to suppress apoptosis. Alpha-lipoic acid, a naturally occurring reactive oxygen species scavenger, has been shown to possess anticancer activity, due to its ability to suppress proliferation and ...